Zhukov, A. V., and A. Y. Andryushchenko. “Relief and Ecological Niche of Mute Swan (Cygnus Olor (Gmelin, 1803)) Wintering in Sivash”. Acta Biologica Sibirica, Vol. 3, no. 2, July 2017, pp. 20-45, doi:10.14258/abs.v3i2.2730.